# 作用域，范围，前缀

a = 10
b = 20


def fuc():
    a = 100
    b = 200
    return a, b


c, d = fuc()
print(a, b, c, d)


# 使用全局作用域中的变量
def fuc2():
    global a
    a = 100  # 将全局的a 更改成100
    b = 200
    return a, b


c, d = fuc2()
print(a, b, c, d)
